William j



(No Model.)

W. J. BOWEN.

MECHANICAL TELEPHONE. No. 285,004. Patented Sept. 18, 1883.

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UNITED STATES PATENT OFFICE.

\VIlLLIAM .T. BOVEN, OF NORXVALK, OHIO, ASSIGNOR TO HIMSELF, T. T. 'KECH- LEE, OE CINCINNATI, OHIO, AND Z. O. THW'ING, OE MARSHALL, MIOH.

MECHANICAL TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 285,004, dated September 18, 1883,

Application filed October 26, 1852. (X0 model.) I

To (LZZ whom, it may concern:

Be it known that 1, WILLIAM J. BowEX, a citizen of the United States, residing at N on walk, in the county of Huron and State of Ohio, have invented certain new and useful Improvements in Mechanical Telephones, of which the following is a full, clear, and exact description.

The object of my invention is to obtain a more perfect operation of mechanical telephones in respect to clearness of sound.

To this end my invention consists in an adjustable dampener, which is so constructed and connected with the diaphragm as to be entirelysupported by and to vibrate with it.

Itcfereiieebeinghad to the accompanying drawings, forming a part of this specification, in which similar letters of reference indicate corresponding parts in both figures,*-Figure 1 is a rear view of the instrument, and Fig. 2 is a cross-section of same.

A, 2, is the diaphragm, clamped between the two sections of the case B B 7) b, usual.

Behind the diaphragm A is a disk, 0, of soft and elastic material, preferably india-rubber, pressed down at its edge upon the diaphragm, from which its center is raised and supported by the tubular rubber spring D.

E E E E are the back-pressure springs, which are fiat metallic springs, fastened to a 'common center, each spring forming an arm radiating out from the center and bent inward, so that their extremities press in toward the diaphragm at different points, and at a short distance from the edge of the disk C, the pressure being adj nstable by means of screw G. The baelcpressure springs E E E E are thickened at the center by soldering on another piece of metal for the purpose of boring and threading to receive the screw G, which passes from the front of the diaphragm back through the washer H and the center of diaphragm A, the tubular rubber spring D, and

the disk 0, and is turned into the center of 4.5

back-pressure springs E E E E, drawing them toward the diaphragm A and forming an adjnstable dampener on the same, preventing c false vibrations and delivering the sound clear supported by and vibrating with said dia 60 phragm, as herein set forth.

2. The combination of the screw G, the backpressure springs E E E E, elastic disk 0, and tubular spring D, with the diaphragm A and case B B b b, substantially as described, and for the purposes set forth.

\VILLIAM J. BOWEN.

W'itnesses Anson T. Bownx, S. T. A. VAN ScIvEn.

It is hereby certified that in Letters Patent No. 285,00l, granted September 18, 1883, upon the application of WVillimn J. Bowen of Norwnlk, Ohio for an improvement in Mechanical Telephones, the name of one of the nssignees was erroneously Written and printed T. T. Keohler; that said name should have been Written and printed T. T. Keokelcr and that the proper correction has been mnrle in the files and records permining to the case in the Patent Oflioe, and shoulcl be read in the Letters Patent to make it conform thereto.

Signed, oount-ersigned, and sealed this 27th day of May, A. D. 188i.

[SEAL] M. L. JOSLYN,

Acting Secretary of the Interior,

Goinltersigneclz BENJ. Bn'rrnnwonrn,

Com missioner of Patents.

Letters Patent No. 285,004

Correction m It is hereby certified that in Letters Patent No. 285,004, granted September 18,1883,

of Norwalk, Ohio, Mechanical Telephones, the name of one of the assignees was erroneously written and printed T. T. Kechler;

T. Keckelcr taining to the case in the Patent Offiee,

upon the application of William J. Bowen, for an improvement in that said name should have been written and printed T. and that the proper correction has been made in the and should be read in the Letters Patent to files and records permake it conform thereto.

Signed, countersigned, and sealed this 27th da of May, A. D. 1884.

{SEALJ M. L. JOSLYN,

Acting Secretary of the Interior.

Countersigned:

BENJ. BUTTERWORTH,

Commissioner of Patents.

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